This invention relates generally to the field of surfactants and more specifically to a process for manufacturing non-estrogenic alkoxylated phenols and alkyl phenols and their anionic derivatives. This invention also involves the application of non-estrogenic alkoxylated phenols and alkyl phenols to various processes including but not limited to, oil recovery, heavy oil transport, de-inking, demulsification, emulsion polymerization, agricultural formulations, coatings and adhesives, mining, personal care products, laundry, and detergents products where the alkyl phenol ethoxylates and their derivatives are applied.
Alkyl phenol and phenol ethoxylates have been used extensively in the past for a wide variety of applications. These include but are not restricted to de-inking, demulsification, emulsion polymerization, agricultural formulations, oil recovery, coatings and adhesives, mining, personal care'products, laundry, and detergents products. They have been found to be among the most economical and effective surfactants. The use of phenol ethoxylates and alkylphenol ethoxylates (APEs) and their anionic derivatives has been severely restricted because they have been found to be estrogenic or their degradation products have been found to be estrogenic. A paper by White, et al in 1994 entitled “Environmentally Persistent Alkylphenolic Compounds are Estrogenic” discussed the estrogenicity of ethoxylated alkylphenols particularly octylphenol, nonylphenol (NP) and nonylphenol with one ethylene oxide (NP1EO). Jobling and Sumpter from Brunel University reported in Aquatic Toxicology1993 that Nonylphenol with one or two moles ethylene oxide (NP2EO) and Nonyl phenol with one ethylene oxide carboxylate (NP1EC) were found to be estrogen mimics. Compared to Estradiol, they found that 4-ter-butylphenol was 1,100 less estrogenic, 4-tert-octylphenol was 1,200 less estrogenic, Nonylphenol was 9,000 times less estrogenic, NP1EO 8,500 times less estrogenic, NP2EO was 9,500 less estrogenic and NP9EO was 45,500 less estrogenic. In their paper, published in the Journal of Biological Chemistry Vol. 272, No. 6 p 3280-3288 (1997), Routledge and Sumpter looked at the structural features of alkylphenolic chemicals associated with estrogenic activity. They found that altering the size and branching of the ethoxylated side chain could affect the extent of estrogenicity. They showed that addition of 2 moles of ethylene oxide to nonylphenol resulted in a 165-fold reduction in estrogenicity and addition of branched propylene oxide (PO) groups resulted in a 35,000-fold reduction in estrogenicity. Addition of two or more moles of PO resulted in complete loss of estrogenicity as also reported in WO 9706125. Addition of propylene oxide to the phenolic ring before ethoxylation results in a product that does not degrade to an estrogen precursor because the phenolic ring has been shown to degrade before the propylene oxide leaving no alkylphenol residue. WO 9706125 describes the use of propylene oxide (PO) to reduce the estrogenicity of ethoxylated phenols and alkylphenols. This patent application confirms that the addition of enough PO prior to ethoxylation will reduce or eliminate estrogenicity. The estrogenicity can be completely eliminated by adding enough PO to insure that all phenolic rings have been completely reacted with at least 1 mole of PO prior the ethoxylation. This generally will take 2 or more moles of PO for each molecule of phenolic starting material. However adding 2 or more moles PO may change the properties of the final surfactant, especially for surfactants containing low amounts of ethylene oxide. The present invention is an improvement over the existing technology by insuring that the estrogenicity of the ethoxylated phenol is completely eliminated using a minimum number of moles of PO and does not affect the final surfactant properties due to the addition of too much PO.
Recently published U.S. Pat. No. 7,435,709 discloses the use of alkylphenol in lubricating oil where the alkylphenol is made from a hydroxyaromatic such as phenol and an olefin having at least 10 carbons and greater than 80 mole % C20-C30 carbons. This product was found to be non-estrogenic however the use of such compounds in many applications is restricted because of their limited or non-water solubility. This type product would require very large amounts of ethylene oxide to render it water soluble. The present invention allows for a much lower chain length for the alkyl group attached to the alkylphenol and for the addition of much less EO to render the product water soluble.